diff --git a/ozon/products.go b/ozon/products.go
index b78a09e..500d4a0 100644
--- a/ozon/products.go
+++ b/ozon/products.go
@@ -27,7 +27,7 @@ type GetStocksInfoParams struct {
 
 type GetStocksInfoFilter struct {
 	// Filter by the offer_id parameter. It is possible to pass a list of values
-	OfferId string `json:"offer_id,omitempty"`
+	OfferId []string `json:"offer_id,omitempty"`
 
 	// Filter by the product_id parameter. It is possible to pass a list of values
 	ProductId int64 `json:"product_id,omitempty"`
diff --git a/ozon/products_test.go b/ozon/products_test.go
index f49aa8c..6b95ecb 100644
--- a/ozon/products_test.go
+++ b/ozon/products_test.go
@@ -26,7 +26,7 @@ func TestGetStocksInfo(t *testing.T) {
 				Limit:  100,
 				LastId: "",
 				Filter: GetStocksInfoFilter{
-					OfferId:    "136834",
+					OfferId:    []string{"136834"},
 					ProductId:  214887921,
 					Visibility: "ALL",
 				},